excel assign 3

IND 503 M2.5 The Link Between Smoking and Cancer Does It Exist?

We all know smoking causes cancer right? How do we know that? What was the true experiment that was conducted to determine this well known fact? How would you test to determine that smoking definitely causes cancer while controlling for all of the other factors that might contribute to an individual developing cancer? Consider this: Cancer has been proven to have a genetic component. Many carcinogens in the environment may contribute to the development of cancer. Many individuals that smoke also engage in other risky behaviors. Now let’s find our sample. To generalize to the entire population, we would need a representation of age groups, races and ethnicities, and gender. Then we would need to confirm that no member of the group has a genetic propensity for cancer through genetic screening. Next, we would need to isolate them all to the same environment, where they are all breathing the same air, drinking and eating the same beverages and foods, use the same personal hygiene items, the same laundry soap and bedding, etc. Now let’s conduct our experiment. Lung cancer rates increase beginning at age 40 and peak at age 70, but no data exists on the amount of time we would need to keep our sample in isolation. Given the data we do have, we would need to determine how long to conduct this longitudinal experiment. We would also need to ensure that they are smoking the same cigarettes, and the same number of cigarettes per day, unless that is, we are interested in how many cigarettes might cause cancer. In that case we might want to have one group smoke 10 cigarettes per day, another group smoke 20 cigarettes per day....and you get the point. This would be the only way to definitively determine a cause and effect relationship between smoking and cancer. In fact, the relationship that exists between the two is just that: a relationship, or to state

in statistical terms – a correlation.

We know that correlation does not equal causation, so why does everyone agree with the statement that smoking causes cancer? Some situations do not lend themselves to true experimentation in the real world and may have severe ethical implications. Let's examine how you can calculate a correlation and regression in Excel.

Video Correlation and Regression with Excel Time: 5:31 mins Auto-Generated Closed Caption